From
International Code of Botanical Nomenclature
(Saint Louis Code), Electronic version
http://www.bgbm.fu-berlin.de/iapt/no....Luistitle.htm

CHAPTER VII. ORTHOGRAPHY AND GENDER OF NAMES
SECTION 1. ORTHOGRAPHY
Article 60

60B.1. When a new generic name, or subgeneric or sectional epithet, is taken
from
the name of a person, it should be formed as follows:
(a) When the name of the person ends with a vowel, the letter -a is added
(thus Ottoa after Otto; Sloanea after Sloane), except when the name ends
with -a, when -ea is added (e.g. Collaea after Colla), or with -ea (as
Correa), when no letter is added.
(b) When the name of the person ends with a consonant, the letters -ia are
added, but when the name ends with -er, either of the terminations -ia
and -a is appropriate (e.g. Sesleria after Sesler and Kernera after Kerner).
(c) In latinized personal names ending with -us this termination is dropped
(e.g. Dillenia after Dillenius) before applying the procedure described
under (a) and (b).

So the answer is yes, assuming -y is a vowel. ...unless Betty kept her own
name. Or hyphenated it. There are rules about hyphenation but I didn't
look them up.

"Steve" wrote in message
...
I have a bad cold and feel like ... well never mind. Just be gentle if I'm
missing something.

What are the rules when a genus is named after a person? Would the genus
named after William Cattley still be called Cattleya if it had been named
after Betty Cattley?

Steve